Chatham County, May 2003

Diagnosis: Orange Rust Disease

This is orange rust of blackberry, caused by the fungus Arthuriomyces peckianus. Orange rust infects black and purple raspberries and most varieties of erect blackberries and trailing blackberries. Red raspberries are resistant. The disease stunts plants and drastically reduces fruit set. The "rusted" leaves will eventually wither and drop, but the fungus will likely have infected the canes. If you have susceptible plants nearby, remove the infected plants before the pustules break open and release spores that could infect new plants.

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This page last updated January 16, 2006.